<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, user-scalable=no,initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>PX</title>
    <style>
        * {
            margin: 0;
            padding: 0;
        }
    </style>
    <style>
        #testbox {
            width: 300px;
            height: 300px;
            background: #f60 url("http://gtms01.alicdn.com/tps/i1/TB1spICLFXXXXbaXpXXZ10i_XXX-450-353.jpg") left top no-repeat;
        }
        
        #testbox2 {
            width: 50px;
            height: 50px;
            background: #f60;
        }
        
        .testBgBox {
            width: 300px;
            height: 220px;
            background: url(./page2.png) 0 -489px no-repeat;
        }
        
        @media screen and (-webkit-min-device-pixel-ratio:2) {
            #testbox2 {
                background: #ff0;
            }
            .testBgBox {
                width: 300px;
                height: 220px;
                background: url(./page2.png) 0 -489px no-repeat;
            }
        }
        
        @media screen and (max-width:768px) {
            /* body {
                background: #6a7960 url(./page.png) left top no-repeat;
            } */
        }
    </style>
</head>

<body>
    <div class="testBgBox"></div>
    <!-- <div id="testbox"></div> -->
    <!-- <div id="testbox2"></div> -->
    <img src="./page.png" width="100%">
    <img src="./page2.png" width="100%">
</body>

</html>